Cargo bed structures in trucks and trailers are conventionally constructed primarily of steel or wood. However, structures made of such materials suffer from several disadvantages. For example, although steel has a number of desirable properties such has high strength, it is also quite heavy and costly to ship. Further, steel is susceptible to corrosive attack when exposed to fresh water, salt water, oxygen, and other environmental elements such as acid rain, road salts, and other chemicals. The rusting and corrosion of steel weakens the structures made therefrom and can eventually lead to structural failure. As with steel, wood is also susceptible to various types of environmental attack, particular rot from weather exposure and damage from termites. These environmental attacks can lead to a drastic reduction in structural strength and compromise the integrity of the overall structure.
Due to the vulnerability of both steel and wood to environmental attack, frequent and costly maintenance is required to increase the useable life of structures made from such materials. For example, frequent painting or other surface treatment is typically necessary to provide a temporary barrier against corrosion or rot.
Although the use of steel and wood suffer from the disadvantages outlined above, their use is still prevalent in cargo bed structures primarily due to availability, relatively ease of machining or other processing, and because the properties of such materials are relatively consistent and well-known. However, in light of the shortcomings of these conventional construction materials, there is an art-recognized continuing need for load-bearing cargo bed structures that are lightweight and strong, as well as resistant to corrosion and other environmental attack even without surface treatment.